UK regulators have launched a public consultation on whether scientists should be allowed to create human-animal hybrid embryos.
Early embryos yield stem cells
Ministers proposed outlawing such work after unfavourable public opinion.
But a recent report from the Science and Technology Committee warned a total ban was "unnecessarily prohibitive" and could harm UK science.
The Human Fertilisation and Embryo Authority (HFEA) will announce its final recommendations in the Autumn.
Applications by King's College London and the University of Newcastle for permission to produce embryos that would be 99.9% human and 0.1% animal have been sent to the HFEA, but have been put on hold.
The HFEA has produced a consultation paper explaining the possible types of embryo research that could done in the future.
For example, using animal eggs to create hybrid embryos from which stem cell lines could be produced.
The resulting embryos would not be allowed to develop past 14 days and implantation would be prohibited
It is hoped their stem cells might help in the fight against conditions such as Alzheimer's or motor neurone disease.
There will be a public meeting in London during June where interest groups, fertility patients, members of the public and scientists will discuss the issues.
An opinion poll of 2,000 people is also planned and anyone can offer their views through an online questionnaire.
Shirley Harrison, chair of the HFEA, said: "The possibility of creating human embryos that contain animal DNA clearly raises key ethical and social questions that we need to take into consideration before deciding whether or not we can permit this type of research.
"Groups who are strongly for or against this type of research often made their views clear to us. But as this is a complex area of science, many other people might feel that they don't know enough about the issue to take part in the debate or give their views."
Dr Sophie Petit-Zeman, head of external relations at the Association of Medical Research Charities, whose members have called for the government to sanction the research, said: "We welcome any initiative that truly engages the public in thinking about medical research in the context of what it can do to help patients."
Professor Robin Lovell-Badge, head of developmental genetics at the MRC National Institute For Medical Research, said he hoped the consultation would promote greater understanding.
"Scientists in the UK and elsewhere have gained much valuable information from such species combinations in other contexts, such as animal-human hybrid cells in culture or human genes in transgenic mice, and as long as obvious barriers are respected, in my opinion there is no reason to fear the types of experiment that are now being proposed."
But Josephine Quintavalle, director of Comment on Reproductive Ethics, said the HFEA did not have a good understanding of the science and a body such as the Royal Society should instead be tasked with running a consultation.
"It is appropriate the public has a chance to debate the issue, but we need to hear much more about the science and from the scientists who are opposed to it."
Dr Evan Harris, the Liberal Democrat MP who led the opposition to the government's proposed ban, said a consultation was not necessary because few people oppose the research who didn't already oppose all embryo research.
But he added: "Since there is a consultation it must be understood that the responses will be informative but scientific research should not be subject to referendum."